hop up rubber, get a systema or prometheus. And then wash it in hot water(people say cold is better but hot water actually gets the grease off easier). Air dry it, and then install it. Clean the barrel while your at it too.
Some people here might tell you to get guarder clear but they don't know what their talking about
And I bet someone's going to come into this thread and write a long essay about their kick ass experience with guarder clear.